US6916867B2

US6916867B2 - Synergistic mixtures of UV-absorbers in polyolefins

Info

Publication number: US6916867B2
Application number: US09/823,041
Authority: US
Inventors: François Gugumus
Original assignee: Ciba Specialty Chemicals Corp
Current assignee: BASF Corp
Priority date: 2000-04-04
Filing date: 2001-03-30
Publication date: 2005-07-12
Also published as: KR20010095225A; JP4944305B2; GB2361005A; AU780925B2; ES2192928B1; KR100716600B1; US20010039304A1; CN1204182C; BE1014092A5; GB0107343D0; CA2809148A1; CA2809148C; NL1017774C2; DE10116305B4; ITMI20010720A1; ITMI20010720A0; FR2807048A1; DE10116305A1; GB2361005B; JP2001354812A

Abstract

The present invention relates to polyolefin compositions which comprise as UV absorber a synergistic mixture of

- a) at least one hydroxybenzophenone and at least one 2-hydroxyphenylbenzotriazole with the proviso that the polyolefin is a high density polyethylene of the “Phillips” type or a polyethylene of the metallocene type;
- b) at least one hydroxybenzophenone and at least one 2-hydroxyphenyltriazine, with the proviso that if the polyolefin is polypropylene, no polyvinylpyridin is present
- c) at least one hydroxybenzophenone and at least one oxanilide;
- d) at least one 2-hydroxyphenylbenzotriazole and at least one oxanilide;
- e) at least one 2-hydroxyphenyltriazine and at least one oxanilide;
- f) at least one hydroxybenzophenone, at least one 2-hydroxyphenylbenzotriazole and at least one oxanilide;
- g) at least one hydroxybenzophenone, at least one oxanilide and at least one 2-hydroxyphenyltriazine; or
- h) at least one 2-hydroxyphenylbenzotriazole, at least one oxanilide and at least one 2-hydroxy phenyltriazine.

Description

The present invention relates to novel polyolefin compositions which contain mixtures of different UV absorbers.

The effects of atmospheric oxygen, moisture and, in particular, UV light result in degradation of the polymer material. This manifests itself, for example, in the loss of mechanical strength, changes in shade and finally total breakdown of the polymer article. As is known, it is possible to retard such degradation processes in polyolefins by the use of suitable stabilizers, and there are numerous prior art documents in this field.

In the coatings field, EP-A-0453 396 discloses that mixtures of hydroxyphenyl-benzotriazole with hydroxybenzophenon or with hydroxyphenyl-s-triazine UV-absorbers lead to synergistic mixtures which prevent the coatings life time unexpectedly long from degradation.

Although there are prior art documents, such as FR 2619 814, which generically disclose the combined use of oxalamide UV absorbers, particularly in coatings, with benzophenone or benzotriazole UV absorbers, there is however no suggestion in the prior art for the instant combinations in polyolefins.

It has now been found that certain combinations of UV absorbers of different chemical structures are capable of substantially preventing the degradation of polyolefins.

The combinations of the present invention provide an unexpected synergistic stabilization effect for polyolefin articles. The effect is not predictable from the absorption spectra and has not been observed with other UV absorber combinations in polyolefins.

One subject of the present invention is a polyolefin composition which comprises as UV absorber a mixture of

a) at least one hydroxybenzophenone and at least one 2-hydroxyphenylbenzotriazole with the proviso that the polyolefin is a high density polyethylene of the “Phillips” type or a polyethylene of the metallocene type;
b) at least one hydroxybenzophenone and at least one 2-hydroxyphenyltriazine, with the proviso that if the polyolefin is polypropylene, no polyvinylpyridin is present
c) at least one hydroxybenzophenone and at least one oxanilide;
d) at least one 2-hydroxyphenylbenzotriazole and at least one oxanilide;
e) at least one 2-hydroxyphenyltriazine and at least one oxanilide;
f) at least one hydroxybenzophenone, at least one 2-hydroxyphenylbenzotriazole and at least one oxanilide;
g) at least one hydroxybenzophenone, at least one oxanilide and at least one 2-hydroxyphenyltriazine; or
h) at least one 2-hydroxyphenylbenzotriazole, at least one oxanilide and at least one 2-hydroxyphenyltriazine.

Suitable polyolefins are mentioned below.

1. Polymers of monoolefins and diolefins, for example polypropylene, polyisobutylene, polybut-1-ene, poly-4-methylpent-1-ene, polyisoprene or polybutadiene, as well as polymers of cycloolefins, for instance of cyclopentene or norbornene, polyethylene (which optionally can be crosslinked), for example high density polyethylene (HDPE), high density and high molecular weight polyethylene (HDPE-HMW), high density and ultrahigh molecular weight polyethylene(HDPE-UHMW), medium density polyethylene (MDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), (VLDPE) and (ULDPE), metallocene polyethylen (m-PE) in particular m-LLDPE and metallocene poylpropylene (m-PP).

Polyolefins, i.e. the polymers of monoolefins exemplified in the preceding paragraph, preferably polyethylene and polypropylene, can be prepared by different, and especially by the following, methods:

- a) radical polymerisation (normally under high pressure and at elevated temperature).
- b) catalytic polymerisation using a catalyst that normally contains one or more than one metal of groups IVb, Vb, VIb or VIII of the Periodic Table. These metals usually have one or more than one ligand, typically oxides, halides, alcoholates, esters, ethers, amines, alkyls, alkenyls and/or aryls that may be either π- or σ-coordinated. These metal complexes may be in the free form or fixed on substrates, typically on activated magnesium chloride, titanium(III) chloride, alumina or silicon oxide. These catalysts may be soluble or insoluble in the polymerisation medium. The catalysts can be used by themselves in the polymerisation or further activators may be used, typically metal alkyls, metal hydrides, metal alkyl halides, metal alkyl oxides or metal alkyloxanes, said metals being elements of groups Ia, IIa and/or IIIa of the Periodic Table. The activators may be modified conveniently with further ester, ether, amine or silyl ether groups. These catalyst systems are usually termed Phillips, Standard Oil Indiana, Ziegler (-Natta), TNZ (DuPont), metallocene or single site catalysts (SSC).

2. Mixtures of the polymers mentioned under 1), for example mixtures of polypropylene with polyisobutylene, polypropylene with polyethylene (for example PP/HDPE, PP/LDPE) and mixtures of different types of polyethylene (for example LDPE/HDPE), metallocene types with conventional types (for example m-PE/PE-LLD, m-PE/PE-LD, m-PP/conventional PP).

Preferably the polyolefin is polyethylene or polypropylene.

Preferred UV-absorber mixtures are:

a) at least one hydroxybenzophenone and at least one 2-hydroxyphenylbenzotriazole with the proviso that the polyolefin is a high density polyethylene of the “Phillips” type or a polyethylene of the metallocene type;
b) at least one hydroxybenzophenone and at least one 2-hydroxyphenyltriazine, with the proviso that if the polyolefin is polypropylene, no polyvinylpyridin is present and;
e) at least one 2-hydroxyphenyltriazine and at least one oxanilide.

Preferred polyolefin compositions are wherein the hydroxybenzophenone is of formula I

the 2-hydroxyphenylbenzotriazole is of formula IIa, IIb or IIc

the 2-hydroxyphenyltriazine is of formula III

and the oxanilide is of formula (IV)

in the compounds of the formula (I) v is an integer from 1 to 3 and w is 1 or 2 and the substituents Z independently of one another are hydrogen, halogen, hydroxyl or alkoxy having 1 to 12 carbon atoms;

in the compounds of the formula (IIa),

R₁is hydrogen, alkyl having 1 to 24 carbon atoms, phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, cycloalkyl having 5 to 8 carbon atoms or a radical of the formula

in which

R₄and R₅independently of one another are alkyl having in each case 1 to 5 carbon atoms, or R₄, together with the radical C_nH_2n+1−m, forms a cycloalkyl radical having 5 to 12 carbon atoms,

m is 1 or 2, n is an integer from 2 to 20 and

M is a radical of the formula —COOR₆in which

R₆is hydrogen, alkyl having 1 to 12 carbon atoms, alkoxyalkyl having in each case 1 to 20 carbon atoms in the alkyl moiety and in the alkoxy moiety or phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety,

R₂is hydrogen, halogen, alkyl having 1 to 18 carbon atoms, and phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, and

R₃is hydrogen, chlorine, alkyl or alkoxy having in each case 1 to 4 carbon atoms or —COOR₆in which R₆is as defined above, at least one of the radicals R₁and R₂being other than hydrogen;

in the compounds of the formula (IIb)

T is hydrogen or alkyl having 1 to 6 carbon atoms,

T₁is hydrogen, chlorine or alkyl or alkoxy having in each case 1 to 4 carbon atoms,

n is 1 or 2 and,

if n is 1,

T₂is chlorine or a radical of the formula —OT₃or

and,

if n is 2, T₂is a radical of the formula

or —O—T₉—O— in which

T₃is hydrogen, alkyl which has 1 to 18 carbon atoms and is unsubstituted or substituted by 1 to 3 hydroxyl groups or by —OCOT₆, alkyl which has 3 to 18 carbon atoms, is interrupted once or several times by —O— or —NT₆— and is unsubstituted or substituted by hydroxyl or —OCOT₆, cycloalkyl which has 5 to 12 carbon atoms and is unsubstituted or substituted by hydroxyl and/or alkyl having 1 to 4 carbon atoms, alkenyl which has 2 to 18 carbon atoms and is unsubstituted or substituted by hydroxyl, phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, or a radical of the formula —CH₂CH(OH)—T₇or

T₄and T₅independently of one another are hydrogen, alkyl having 1 to 18 carbon atoms, alkyl which has 3 to 18 carbon atoms and is interrupted once or several times by —O— or —NT₆—, cycloalkyl having 5 to 12 carbon atoms, phenyl, phenyl which is substituted by alkyl having 1 to 4 carbon atoms, alkenyl having 3 to 8 carbon atoms, phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety or hydroxyalkyl having 2 to 4 carbon atoms,

T₆is hydrogen, alkyl having 1 to 18 carbon atoms, cycloalkyl having 5 to 12 carbon atoms, alkenyl having 3 to 8 carbon atoms, phenyl, phenyl which is substituted by alkyl having 1 to 4 carbon atoms, phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety,

T₇is hydrogen, alkyl having 1 to 18 carbon atoms, phenyl which is unsubstituted or substituted by hydroxyl, phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, or —CH₂OT₈,

T₈is alkyl having 1 to 18 carbon atoms, alkenyl having 3 to 8 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, phenyl, phenyl which is substituted by alkyl having 1 to 4 carbon atoms, or phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety,

T₉is alkylene having 2 to 8 carbon atoms, alkenylene having 4 to 8 carbon atoms, alkynylene having 4 carbon atoms, cyclohexylene, alkylene which has 2 to 8 carbon atoms and is interrupted once or several times by —O—, or a radical of the formula —CH₂CH(OH)CH₂OT₁₁OCH₂CH(OH)CH₂— or —CH₂—C(CH₂OH)₂—CH₂—,

T₁₀is alkylene which has 2 to 20 carbon atoms and can be interrupted once or several times by —O—, or cyclohexylene,

T₁₁is alkylene having 2 to 8 carbon atoms, alkylene which has 2 to 18 carbon atoms and is interrupted once or several times by —O—, 1,3-cyclohexylene, 1,4-cyclohexylene, 1,3-phenylene or 1,4-phenylene, or

T₁₀and T₆, together with the two nitrogen atoms, are a piperazine ring;

in the compounds of formula (IIc)

R′₂is C₁-C₁₂alkyl and k is a number from 1 to 4;

in the compounds of the formula (III)

u is 1 or 2 and r is an integer from 1 to 3, the substituents

Y₁independently of one another are hydrogen, hydroxyl, halogenomethyl, alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 18 carbon atoms, or halogen,

if u is 1,

Y₂is alkyl having 1 to 18 carbon atoms, phenoxy which is unsubstituted or substituted by hydroxyl, alkoxy having 1 to 18 carbon atoms, or halogen, or is substituted by alkyl or alkoxy having in each case 1 to 18 carbon atoms or halogen, alkyl which has 1 to 12 carbon atoms and is substituted by —COOH, —COOY₈, —CONH₂, —CONHY₉, —CONY₉Y₁₀, —NH₂, —NHY₉, —NY₉Y₁₀, —NHCOY₁₁, —CN and/or —OCOY₁₁, alkyl which has 4 to 20 carbon atoms, is interrupted by one or more oxygen atoms and is unsubstituted or substituted by hydroxyl or alkoxy having 1 to 12 carbon atoms, alkenyl having 3 to 6 carbon atoms, glycidyl, cyclohexyl which is unsubstituted or substituted by hydroxyl, alkyl having 1 to 4 carbon atoms and/or —OCOY₁₁, phenylalkyl which has 1 to 5 carbon atoms in the alkyl moiety and is unsubstituted or substituted by hydroxyl, chlorine and/or methyl, —COY₁₂or —SO₂Y₁₃, or,

if u is 2,

Y₂is alkylene having 2 to 16 carbon atoms, alkenylene having 4 to 12 carbon atoms, xylylene, alkylene which has 3 to 20 carbon atoms, is interrupted by one or more —O— atoms and/or is substituted by hydroxyl, —CH₂CH(OH)CH₂—O—Y₁₅—OCH₂CH(OH)CH₂, —CO—Y₁₆—CO—, —CO—NH—Y₁₇—NH—CO— or —(CH₂)_m—CO₂—Y₁₈—OCO—(CH₂)_m, in which

m is 1, 2 or 3,

Y₈is alkyl having 1 to 18 carbon atoms, alkenyl having 3 to 18 carbon atoms, alkyl which has 3 to 20 carbon atoms, is interrupted by one or more oxygen or sulfur atoms or —NT₆— and/or is substituted by hydroxyl, alkyl which has 1 to 4 carbon atoms and is substituted by —P(O)(OY₁₄)₂, —NY₉Y₁₀or —OCOY₁₁and/or hydroxyl, alkenyl having 3 to 18 carbon atoms, glycidyl, or phenylalkyl having 1 to 5 carbon atoms in the alkyl moiety,

Y₉and Y₁₀independently of one another are alkyl having 1 to 12 carbon atoms, alkoxyalkyl having 3 to 12 carbon atoms, dialkylaminoalkyl having 4 to 16 carbon atoms or cyclohexyl having 5 to 12 carbon atoms, or Y₉and Y₁₀together are alkylene, oxaalkylene or azaalkylene having in each case 3 to 9 carbon atoms,

Y₁₁is alkyl having 1 to 18 carbon atoms, alkenyl having 2 to 18 carbon atoms or phenyl,

Y₁₂is alkyl having 1 to 18 carbon atoms, alkenyl having 2 to 18 carbon atoms, phenyl, alkoxy having 1 to 12 carbon atoms, phenoxy, alkylamino having 1 to 12 carbon atoms or phenylamino,

Y₁₃is alkyl having 1 to 18 carbon atoms, phenyl or alkylphenyl having 1 to 8 carbon atoms in the alkyl radical,

Y₁₄is alkyl having 1 to 12 carbon atoms or phenyl,

Y₁₅is alkylene having 2 to 10 carbon atoms, phenylene or a group -phenylene-M-phenylene- in which M is —O—, —S—, —SO₂—, —CH₂— or —C(CH₃)₂—,

Y₁₆is alkylene, oxaalkylene or thiaalkylene having in each case 2 to 10 carbon atoms, phenylene or alkenylene having 2 to 6 carbon atoms,

Y₁₇is alkylene having 2 to 10 carbon atoms, phenylene or alkylphenylene having 1 to 11 carbon atoms in the alkyl moiety, and

Y₁₈is alkylene having 2 to 10 carbon atoms or alkylene which has 4 to 20 carbon atoms and is interrupted once or several times by oxygen;

in the compounds of the formula (IV) x is an integer from 1 to 3 and the substituents L independently of one another are hydrogen, alkyl, alkoxy or alkylthio having in each case 1 to 22 carbon atoms, phenoxy or phenylthio.

In the compounds of the formula (IIa) R₁can be hydrogen or alkyl having 1 to 24 carbon atoms, such as methyl, ethyl, propyl, butyl, hexyl, octyl, nonyl, dodecyl, tetradecyl, hexadecyl, octadecyl, nonadecyl and eicosyl and also corresponding branched isomers. Furthermore, in addition to phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, for example benzyl, R₁can also be cycloalkyl having 5 to 8 carbon atoms, for example

cyclopentyl, cyclohexyl and cyclooctyl, or a radical of the formula

in which R₄and R₅independently of one another are alkyl having in each case 1 to 5 carbon atoms, in particular methyl, or R₄, together with the C_nH_2n+1−mradical, forms a cycloalkyl radical having 5 to 12 carbon atoms, for example cyclohexyl, cyclooctyl and cyclodecyl. M is a radical of the formula —COOR₆in which R₆is not only hydrogen but also alkyl having 1 to 12 carbon atoms or alkoxyalkyl having 1 to 20 carbon atoms in each of the alkyl and alkoxy moieties. Suitable alkyl radicals R₆are those enumerated for R₁. Examples of suitable alkoxyalkyl groups are —C₂H₄OC₂H₅, —C₂H₄OC₈H₁₇and —C₄H₈OC₄H₉. As phenylalkyl having 1 to 4 carbon atoms, R₆is, for example, benzyl, cumyl, α-methylbenzyl or phenylbutyl.

In addition to hydrogen and halogen, for example chlorine and bromine, R₂can also be alkyl having 1 to 18 carbon atoms. Examples of such alkyl radicals are indicated in the definitions of R₁. R₂can also be phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, for example benzyl, a-methylbenzyl and cumyl.

Halogen as a substituent means in all cases fluorine, chlorine, bromine or iodine, preferably chlorine or bromine and more preferably chlorine.

At least one of the radicals R₁and R₂must be other than hydrogen.

In addition to hydrogen or chlorine, R₃is also alkyl or alkoxy having in each case 1 to 4 carbon atoms, for example methyl, butyl, methoxy and ethoxy, and also —COOR₆.

In the compounds of the formula (IIb) T is hydrogen or alkyl having 1 to 6 carbon atoms, such as methyl and butyl, T₁is not only hydrogen or chlorine, but also alkyl or alkoxy having in each case 1 to 4 carbon atoms, for example methyl, methoxy and butoxy, and, if n is 1, T₂is chlorine or a radical of the formula —OT₃or —NT₄T₅. T₃is here hydrogen or alkyl having 1 to 18 carbon atoms (cf. the definition of R₁). These alkyl radicals can be substituted by 1 to 3 hydroxyl groups or by a radical —OCOT₆. Furthermore, T₃can be alkyl having 3 to 18 carbon atoms (cf. the definition of R₁) which is interrupted once or several times by —O— or —NT₆— and is unsubstituted or substituted by hydroxyl or —OCOT₆. Examples of T₃as cycloalkyl are cyclopentyl, cyclohexyl or cyclooctyl. T₃can also be alkenyl having 2 to 18 carbon atoms. Suitable alkenyl radicals are derived from the alkyl radicals enumerated in the definitions of R₁. These alkenyl radicals can be substituted by hydroxyl. Examples of T₃as phenylalkyl are benzyl, phenylethyl, cumyl, α-methylbenzyl or benzyl. T₃can also be a radical of the formula —CH₂CH(OH)—T₇or

Like T₃, T₄and T₅can, independently of one another, be not only hydrogen but also alkyl having 1 to 18 carbon atoms or alkyl which has 3 to 18 carbon atoms and is interrupted once or several times by —O— or —NT₆—. T₄and T₅can also be cycloalkyl having 5 to 12 carbon atoms, for example cyclopentyl, cyclohexyl and cyclooctyl. Examples of T₄and T₅as alkenyl groups can be found in the illustrations of T₃. Examples of T₄and T₅as phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety are benzyl or phenylbutyl. Finally, these substituents can also be hydroxyalkyl having 1 to 3 carbon atoms.

If n is 2, T₂is a divalent radical of the formula

or —O—T₉—O—.

In addition to hydrogen, T₆(see above also) is alkyl, cycloalkyl, alkenyl, aryl or phenylalkyl; examples of such radicals have already been given above.

In addition to hydrogen and the phenylalkyl radicals and long-chain alkyl radicals mentioned above, T₇can be phenyl or hydroxyphenyl and also —CH₂OT₈in which T₈can be one of the alkyl, alkenyl, cycloalkyl, aryl or phenylalkyl radicals enumerated.

The divalent radical T₉can be alkylene having 2 to 8 carbon atoms, and such radicals can also be branched. This also applies to the alkenylene and alkynylene radicals T₉. As well as cyclohexylene, T₉can also be a radical of the formula —CH₂CH(OH)CH₂OT₁₁OCH₂CH(OH)CH₂— or —CH₂—C(CH₂OH)₂—CH₂—.

T₁₀is a divalent radical and, in addition to cyclohexylene, is also alkylene which has 2 to 20 carbon atoms and which can be interrupted once or several times by —O—. Suitable alkylene radicals are derived from the alkyl radicals mentioned in the definitions of R₁.

T₁₁is also an alkylene radical. It contains 2 to 8 carbon atoms or, if it is interrupted once or several times by —O—, 4 to 10 carbon atoms. T₁₁is also 1,3-cyclohexylene, 1,4-cyclohexylene, 1,3-phenylene or 1,4-phenylene.

Together with the two nitrogen atoms, T₆and T₁₀can also be a piperazine ring.

Examples of alkyl, alkoxy, phenylalkyl, alkylene, alkenylene, alkoxyalkyl and cycloalkyl radicals and also alkylthio, oxaalkylene or azoalkylene radicals in the compounds of the formulae (2), (3) and (4) can be deduced from the above statements.

The UV absorbers of the formulae (I), (IIa), (IIb), (IIc), (III) and (IV) are known per se and are described, together with their preparation, in, for example, EP-A-323 408, EP-A-57 160, U.S. Pat. No. 5,736,597 (EP-A-434 608), U.S. Pat. No. 4,619,956, DE-A 31 35 810 and GB-A 1 336 391. Preferred meanings of substituents and individual compounds can be deduced from the documents mentioned.

The compounds can be incorporated into polyolefins by customary methods which are known per se. The preparation may be carried out in a manner known per se by mixing the said components and, if desired, further additives with the polymer using devices known per se, such as calenders, mixers, kneaders, extruders and the like. The additives may be added individually or in admixture with one another. It is also possible to use so-called master batches.

In certain cases it can be advantageous to use even a mixture of compounds of all 4 classes of UV-absorbers (hydroxybenzophenone, 2-hydroxyphenyltriazine, oxanilide and 2-hydroxyphenylbenzotriazole).

The polyolefin composition obtainable according to the present invention can be made into the desired form in known manner. Such processes include, for example, grinding, calendering, extruding, injection-moulding, sintering, compression/sintering or spinning, also extrusion blow-moulding.

The amounts of UV absorber to be selected can depend on the nature of the polyolefin composition and the requirements for its stability. The individual UV absorber components can be added on their own or as a mixture to the appropriate polyolefin compositions. The customary other additives, such as processing stabilizers, antioxidants and other light stabilisers, can also be added to the polyolefin compositions, without thereby impairing the protective action of the UV absorber mixtures employed in accordance with the invention.

Preferred is a polyolefin composition wherein the substituent R₁or R₂in the compounds of the formula (IIa) is located in the ortho-position or para-position relative to the hydroxyl group.

Also preferred is a polyolefin composition, in which, in the compounds of the formula (IIa), R₁is hydrogen or alkyl having 1 to 20 carbon atoms, R₂is hydrogen, alkyl having 1 to 18 carbon atoms or phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety and R₃is hydrogen, chlorine or alkyl having 1 to 4 carbon atoms. Preference is given to compounds, in which R₁is in the ortho-position relative to the hydroxyl group and is hydrogen or alkyl having 4 to 12 carbon atoms, R₂is in the para-position relative to the hydroxyl group and is alkyl having 1 to 6 carbon atoms or cumyl and R₃is hydrogen or chlorine. More preferably R₁is alkyl having 8 to 12 carbon atoms, R₂is alkyl having 4 to 6 carbon atoms and R₃is hydrogen.

Other preferred polyolefin compositions are those, in which, in the compounds of the formula (IIb), T is alkyl having 1 to 6 carbon atoms, T₁is hydrogen, chlorine or alkyl having 1 to 4 carbon atoms, n is 1 or 2 and, if n is 1, T₂is one of the radicals of the formula —OT₃or

and, if n is 2, T₂is a radical of the formula —O—T₉—O— or

in which T₃is hydrogen, alkyl having 1 to 18 carbon atoms or alkyl which has 3 to 18 carbon atoms and is interrupted once or several times by —O—, T₄and T₅independently of one another are hydrogen, alkyl having 1 to 18 carbon atoms, alkenyl having 3 to 8 carbon atoms or hydroxyalkyl having 2 to 4 carbon atoms, T₆is hydrogen or alkyl having 1 to 6 carbon atoms, and T₉and T₁₀are alkylene having 2 to 8 carbon atoms, alkenylene having 4 to 8 carbon atoms or alkylene which has 2 to 18 carbon atoms and is interrupted once or several times by —O—.

More preferably, in which T is alkyl having 1 to 4 carbon atoms, T₁is hydrogen or chlorine and T₂is one of the radicals of the formula —OT₃or —O—T₉—O— in which T₃is hydrogen, alkyl having 1 to 12 carbon atoms or a radical of the formula —(OC₂H₄)_4-8——H and T₉is alkylene having 2 to 8 carbon atoms.

Most preferably T₂is a radical of the formula —OT₃and T₃is alkyl having 1 to 12 carbon atoms or a radical of the formula —(OC₂H₄)_4-8—H.

Further preferred polyolefin compositions are those, in which, in the compounds of the formula (III), the substituents Y₁are hydrogen, alkyl having 1 to 12 carbon atoms or halogen, if u is 1, Y₂is alkyl having 1 to 18 carbon atoms, alkyl which has 1 to 12 carbon atoms and is substituted by hydroxyl, alkoxy having 1 to 18 carbon atoms, —COOY₈, —CONY₉Y₁₀and/or —OCOY₁₁, glycidyl or phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, or, if u is 2, Y₂is alkylene having 2 to 16 carbon atoms, alkenylene having 4 to 12 carbon atoms, xylylene or alkylene which has 3 to 20 carbon atoms, is interrupted by one or more —O— atoms and/or is substituted by hydroxyl, the substituents Y₈to Y₁₁being as defined above.

Prefererably Y₁are hydrogen, alkyl having 1 to 4 carbon atoms or chlorine, if u is 1, Y₂is alkyl which has 1 to 4 carbon atoms and is unsubstituted or substituted by hydroxyl, alkoxy having 1 to 18 carbon atoms, —COOY₈, —CONY₉Y₁₀and/or —OCOY₁₁, glycidyl or benzyl, or, if u is 2, Y₂is alkylene having 6 to 12 carbon atoms, butenylene, xylylene or alkylene which has 3 to 20 carbon atoms, is interrupted by one or more —O— atoms and/or is substituted by hydroxyl, Y₈being alkyl having 4 to 12 carbon atoms, alkenylene having 12 to 18 carbon atoms or alkyl which has 6 to 20 carbon atoms, is interrupted by one or more —O— atoms and/or is substituted by hydroxyl, Y₉and Y₁₀independently of one another being alkyl having 4 to 8 carbon atoms and Y₁₁being alkyl having 1 to 8 carbon atoms or alkenyl having 2 or 3 carbon atoms.

More preferably u is 1 and r is 2, Y₁is alkyl having 1 to 4 carbon atoms and Y₂is alkyl having 1 to 18 carbon atoms or alkyl which has 1 to 12 carbon atoms and is substituted by hydroxyl, alkoxy having 1 to 18 carbon atoms, —COOY₈and/or —OCOY₁₁, Y₈being alkyl having 1 to 18 carbon atoms, alkenyl having 3 to 18 carbon atoms or alkyl which has 3 to 20 carbon atoms, is interrupted by one or more oxygen atoms and/or is substituted by hydroxyl, and Y₁₁being alkenyl having 2 to 18 carbon atoms.

Particularly prefered are the compounds of formula (III), in which Y₂is alkyl having 1 to 8 carbon atoms or alkyl which has 1 to 4 carbon atoms and is substituted by hydroxyl, alkoxy having 12 to 15 carbon atoms, —COOY₈and/or —OCOY₁₁, Y₈being alkyl having 8 to 12 carbon atoms, alkenyl having 12 to 18 carbon atoms or alkyl which has 5 to 10 carbon atoms, is interrupted by an oxygen atom and is substituted by hydroxyl, and Y₁₁being alkenyl having 2 to 8 carbon atoms.

Most preferred are compounds of formula (III), in which Y₁is methyl and Y₂is an octyl radical or alkyl which has 1 to 3 carbon atoms and is substituted by hydroxyl, alkoxy having 13 or 15 carbon atoms, —COOY₈and/or —OCOY₁₁, Y₈being a decyl or octadecenyl radical or alkyl which has 7 carbon atoms and is substituted by hydroxyl and interrupted by an oxygen atom, and Y₁₁being propenyl.

A further preferred polyolefin composition is, in which, in the compounds of the formula (I), v and w independently of one another are 1 or 2 and the substituents Z independently of one another are hydrogen, halogen or alkoxy having 1 to 12 carbon atoms.

Also preferred is a composition, in which, in the compounds of the formula (IV), x and y are 1 or 2 and the substituents L independently of one another are hydrogen or alkyl having in each case 1 to 12 carbon atoms.

Individual UV-absorbers suitable in the present invention are given below.

2-Hydroxybenzophenones, for example the 4-hydroxy, 4-methoxy, 4-octyloxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy, 4,2′,4′-trihydroxy and 2′-hydroxy-4,4′-dimethoxy derivatives.

2-(2′-Hydroxyphenyl)benzotriazoles, for example 2-(2′-hydroxy-5′-methylphenyl)-benzotriazole, 2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)benzotriazole, 2-(5′-tert-butyl-2′-hydroxyphenyl)benzotriazole, 2-(2′-hydroxy-5′-(1,1,3,3-tetramethylbutyl)phenyl)benzotriazole, 2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)-5-chloro-benzotriazole, 2-(3′-tert-butyl-2′-hydroxy-5′-methylphenyl)-5-chloro-benzotriazole, 2-(3′-sec-butyl-5′-tert-butyl-2′-hydroxyphenyl)benzotriazole, 2-(2′-hydroxy-4′-octyloxyphenyl)benzotriazole, 2-(3′,5′-di-tert-amyl-2′-hydroxyphenyl)benzotriazole, 2-(3′,5′-bis-(α,α-dimethylbenzyl)-2′-hydroxyphenyl)benzotriazole, 2-(3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl)-5-chloro-benzotriazole, 2-(3′-tert-butyl-5′-[2-(2-ethylhexyloxy)-carbonylethyl]-2′-hydroxyphenyl)-5-chloro-benzotriazole, 2-(3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)phenyl)-5-chloro-benzotriazole, 2-(3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)phenyl)benzotriazole, 2-(3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl)benzotriazole, 2-(3′-tert-butyl-5′-[2-(2-ethylhexyloxy)carbonylethyl]-2′-hydroxyphenyl)benzotriazole, 2-(3′-dodecyl-2′-hydroxy-5′-methylphenyl)benzotriazole, 2-(3′-tert-butyl-2′-hydroxy-5′-(2-isooctyloxycarbonylethyl)phenylbenzotriazole, 2,2′-methylene-bis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazole-2-ylphenol]; the transesterification product of 2-[3′-tert-butyl-5′-(2-methoxycarbonylethyl)-2′-hydroxyphenyl]-2H-benzotriazole with polyethylene glycol 300; [R—CH₂CH₂—COO—CH₂CH₂₂where R=3′-tert-butyl-4′-hydroxy-5′-2H-benzotriazol-2-ylphenyl, 2-[2′-hydroxy-3′-(α,α-dimethylbenzyl)-5′-(1,1,3,3-tetramethylbutyl)-phenyl]benzotriazole; 2-[2′-hydroxy-3′-(1,1,3,3-tetramethylbutyl)-5′-(α,α-dimethylbenzyl)-phenyl]benzotriazole.

2-(2-Hydroxyphenyl)-1,3,5-triazines, for example 2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-propyloxyphenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis-(4-methylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-tridecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-butyloxypropoxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-octyloxy-propyloxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine, 2-[4-(dodecyloxy/tridecyloxy-2-hydroxypropoxy)-2-hydroxy-phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-dodecyloxy-propoxy)phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-hexyloxy)phenyl-4,6-diphenyl-1,3,5-triazine, 2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-1,3,5-triazine, 2,4,6-tris[2-hydroxy-4-(3-butoxy-2-hydroxy-propoxy)phenyl]-1,3,5-triazine, 2-(2-hydroxyphenyl)-4-(4-methoxyphenyl)-6-phenyl-1,3,5-triazine, 2-{2-hydroxy-4-[3-(2-ethylhexyl-1-oxy)-2-hydroxypropyloxy]phenyl}-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine.

Oxamides, for example 4,4′-dioctyloxyoxanilide, 2,2′-diethoxyoxanilide, 2,2′-dioctyloxy-5,5′-di-tert-butoxanilide, 2,2′-didodecyloxy-5,5′-di-tert-butoxanilide, 2-ethoxy-2′-ethyloxanlide, N,N′-bis(3-dimethylaminopropyl)oxamide, 2-ethoxy-5-tert-butyl-2′-ethoxanilide and its mixture with 2-ethoxy-2′-ethyl-5,4′-di-tert-butoxanilide, mixtures of o- and p-methoxy-disubstituted oxanilides and mixtures of o- and p-ethoxy-disubstituted oxanilides.

Preferably the amount of the individual UV absorber in the mixture is from 20% to 80% based on the weight of the mixture, with the proviso that the sum of the individual components adds to 100%.

Preferably the total amount of the UV-absorber mixture is from 0.005 to 5% based on the weight of the polymer.

Also preferred is a polyolefin composition, which additionally contains at least one sterically hindered amine, in particular an amine of this type containing at least one radical of the formula

in which R is hydrogen or methyl.

Examples of such sterically hindered amines are bis(2,2,6,6-tetramethyl-4-piperidyl)-sebacate, bis(2,2,6,6-tetramethyl-4-piperidyl)succinate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate, bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) n-butyl-3,5-di-tert-butyl-4-hydroxybenzylmalonate, the condensate of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid, linear or cyclic condensates of N,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 4-tert-octylamino-2,6-dichloro-1,3,5-triazine, tris(2,2,6,6-tetramethyl-4-piperidyl)nitrilotriacetate, tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butane-tetracarboxylate, 1,1′-(1,2-ethanediyl)-bis(3,3,5,5-tetramethylpiperazinone), 4-benzoyl-2,2,6,6-tetramethylpiperidine, 4-stearyloxy-2,2,6,6-tetramethylpiperidine, bis(1,2,2,6,6-pentamethylpiperidyl)-2-n-butyl-2-(2-hydroxy-3,5-di-tert-butylbenzyl)malonate, 3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4,5]-decan-2,4-dione, bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl)sebacate, bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl)succinate, linear or cyclic condensates of N,N′-bis-(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 4-morpholino-2,6-dichloro-1,3,5-triazine, the condensate of 2-chloro-4,6-bis(4-n-butylamino-2,2,6,6-tetramethylpiperidyl )-1,3,5-triazine and 1,2-bis(3-aminopropylamino)ethane, the condensate of 2-chloro-4,6-di-(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazine and 1,2-bis-(3-aminopropylamino)ethane, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4,5]decane-2,4-dione, 3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl)pyrrolidin-2,5-dione, 3-dodecyl-1-(1,2,2,6,6-pentamethyl-4-piperidyl)pyrrolidine-2,5-dione, a mixture of 4-hexadecyloxy- and 4-stearyloxy-2,2,6,6-tetramethylpiperidine, a condensation product of N,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 4-cyclohexylamino-2,6-dichloro-1,3,5-triazine, a condensation product of 1,2-bis(3-aminopropylamino)ethane and 2,4,6-trichloro-1,3,5-triazine as well as 4-butylamino-2,2,6,6-tetramethylpiperidine (CAS Reg. No. [136504-96-6]); N-(2,2,6,6-tetramethyl-4-piperidyl)-n-dodecylsuccinimid, N-(1,2,2,6,6-pentamethyl-4-piperidyl)-n-dodecylsuccinimid, 2-undecyl-7,7,9,9-tetramethyl-1-oxa-3,8-diaza-4-oxo-spiro[4,5]decane, a reaction product of 7,7,9,9-tetramethyl-2-cycloundecyl-1-oxa-3,8-diaza-4-oxospiro [4,5]decane und epichlorohydrin, 1,1-bis(1,2,2,6,6-pentamethyl-4-piperidyloxycarbonyl)-2-(4-methoxyphenyl)ethene, N,N′-bis-formyl-N,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine, diester of 4-methoxy-methylene-malonic acid with 1,2,2,6,6-pentamethyl-4-hydroxypiperidine, poly[methylpropyl-3-oxy-4-(2,2,6,6-tetramethyl-4-piperidyl)]siloxane, reaction product of maleic acid anhydride-a-olefin-copolymer with 2,2,6,6-tetramethyl-4-aminopiperidine or 1,2,2,6,6-pentamethyl-4-aminopiperidine.

The polyolefin composition may contain further additives. Examples are given below.

1 Antioxidants

1.1. Alkylated monophenols, for example 2,6-di-tert-butyl-4-methylphenol, 2-tert-butyl-4,6-di-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol, 2,6-di-tert-butyl-4-isobutylphenol, 2,6-dicyclopentyl-4-methylphenol, 2-(α-methylcyclohexyl)-4,6-dimethylphenol, 2,6-dioctadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol, 2,6-di-tert-butyl-4-methoxymethylphenol, nonylphenols which are linear or branched in the side chains, for example, 2,6-di-nonyl-4-methylphenol, 2,4-dimethyl-6-(1′-methylundec-1′-yl)phenol, 2,4-dimethyl-6-(1′-methylheptadec-1′-yl)phenol, 2,4-dimethyl-6-(1′-methyltridec-1′-yl)phenol and mixtures thereof.

1.2. Alkylthiomethylphenols, for example 2,4-dioctylthiomethyl-6-tert-butylphenol, 2,4-dioctylthiomethyl-6-methylphenol, 2,4-dioctylthiomethyl-6-ethylphenol, 2,6-di-dodecylthiomethyl-4-nonylphenol.

1.3. Hydroquinones and alkylated hydroquinones, for example 2,6-di-tert-butyl-4-methoxyphenol, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, 2,6-diphenyl-4-octadecyloxyphenol, 2,6-di-tert-butylhydroquinone, 2,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyphenyl stearate, bis-(3,5-di-tert-butyl-4-hydroxyphenyl) adipate.

1.4. Tocopherols, for example α-tocopherol, β-tocopherol, γ-tocopherol, δ-tocopherol and mixtures thereof (Vitamin E).

1.5. Hydroxylated thiodiphenyl ethers, for example 2,2′-thiobis(6-tert-butyl-4-methylphenol), 2,2′-thiobis(4-octylphenol), 4,4′-thiobis(6-tert-butyl-3-methylphenol), 4,4′-thiobis(6-tert-butyl-2-methylphenol), 4,4′-thiobis-(3,6-di-sec-amylphenol), 4,4′-bis(2,6-dimethyl-4-hydroxyphenyl)disulfide.

1.6. Alkylidenebisphenols, for example 2,2′-methylenebis(6-tert-butyl-4-methylphenol), 2,2′-methylenebis(6-tert-butyl-4-ethylphenol), 2,2′-methylenebis[4-methyl-6-(α-methylcyclohexyl)-phenol], 2,2′-methylenebis(4-methyl-6-cyclohexylphenol), 2,2′-methylenebis(6-nonyl-4-methylphenol), 2,2′-methylenebis(4,6-di-tert-butylphenol), 2,2′-ethylidenebis(4,6-di-tert-butylphenol), 2,2′-ethylidenebis(6-tert-butyl-4-isobutylphenol), 2,2′-methylenebis[6-(α-methylbenzyl)-4-nonylphenol], 2,2′-methylenebis[6-(α,α-dimethylbenzyl)-4-nonylphenol], 4,4′-methylenebis(2,6-di-tert-butylphenol), 4,4′-methylenebis(6-tert-butyl-2-methylphenol), 1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, 2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol, 1,1,3-tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, 1,1-bis(5-tert-butyl-4-hydroxy-2-methyl-phenyl)-3-n-dodecylmercaptobutane, ethylene glycol bis[3,3-bis(3′-tert-butyl-4′-hydroxyphenyl)butyrate], bis(3-tert-butyl-4-hydroxy-5-methyl-phenyl)dicyclopentadiene, bis[2-(3′-tert-butyl-2′-hydroxy-5′-methylbenzyl)-6-tert-butyl-4-methylphenyl]terephthalate, 1,1-bis-(3,5-dimethyl-2-hydroxyphenyl)butane, 2,2-bis-(3,5-di-tert-butyl-4-hydroxyphenyl)propane, 2,2-bis-(5-tert-butyl-4-hydroxy2-methylphenyl)-4-n-dodecylmercaptobutane, 1,1,5,5-tetra-(5-tert-butyl-4-hydroxy-2-methylphenyl)pentane.

1.7. O-, N- and S-benzyl compounds, for example 3,5,3′,5′-tetra-tert-butyl-4,4′-dihydroxydibenzyl ether, octadecyl-4-hydroxy-3,5-dimethylbenzylmercaptoacetate, tridecyl-4-hydroxy-3,5-di-tert-butylbenzylmercaptoacetate, tris(3,5-di-tert-butyl-4-hydroxybenzyl)amine, bis(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)dithioterephthalate, bis(3,5-di-tert-butyl-4-hydroxybenzyl)sulfide, isooctyl-3,5-di-tert-butyl-4-hydroxybenzylmercaptoacetate.

1.8. Hydroxybenzylated malonates, for example dioctadecyl-2,2-bis-(3,5-di-tert-butyl-2-hydroxybenzyl)-malonate, di-octadecyl-2-(3-tert-butyl-4-hydroxy-5-methylbenzyl)-malonate, didodecylmercaptoethyl-2,2-bis-(3,5-di-tert-butyl-4-hydroxybenzyl)malonate, bis[4-(1,1,3,3-tetramethylbutyl)phenyl]-2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate.

1.9. Aromatic hydroxybenzyl compounds, for example 1,3,5-tris-(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, 1,4-bis(3,5-di-tert-butyl-4-hydroxybenzyl)-2,3,5,6-tetramethylbenzene, 2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)phenol.

1.10. Triazine Compounds, for example 2,4-bis(octylmercapto)-6-(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,3,5-triazine, 2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,2,3-triazine, 1,3,5-tris-(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate, 2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenylethyl)-1,3,5-triazine, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-hexahydro-1,3,5-triazine, 1,3,5-tris(3,5-dicyclohexyl-4-hydroxybenzyl)isocyanurate.

1.11. Benzylphosphonates, for example dimethyl-2,5-di-tert-butyl-4-hydroxybenzylphosphonate, diethyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate, dioctadecyl3,5-di-tert-butyl-4-hydroxybenzylphosphonate, dioctadecyl-5-tert-butyl-4-hydroxy-3-methylbenzylphosphonate, the calcium salt of the monoethyl ester of 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid.

1.12. Acylaminophenols, for example 4-hydroxylauranilide, 4-hydroxystearanilide, octyl N-(3,5-di-tert-butyl-4-hydroxyphenyl)carbamate.

1.13. Esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, n-octanol, i-octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N,N′-bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.14. Esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, n-octanol, i-octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N,N′-bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.15. Esters of β-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N,N′-bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.16. Esters of 3,5-di-tert-butyl-4-hydroxyphenyl acetic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N,N′-bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.17. Amides of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid e.g. N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexamethylenediamide, N,N′-bis(3,5-di-tert-butyl-4-hydroxy phenylpropionyl)trimethylenediamide, N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-hydrazide, N,N′-bis[2-(3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyloxy)ethyl]oxamide (Naugard®XL-1 supplied by Uniroyal).

1.18. Ascorbic acid (vitamin C)

1.19. Aminic antioxidants, for example N,N′-di-isopropyl-p-phenylenediamine, N,N′-di-sec-butyl-p-phenylenediamine, N,N′-bis(1,4-dimethylpentyl)-p-phenylenediamine, N,N′-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine, N,N′-bis(1-methylheptyl)-p-phenylenediamine, N,N′-dicyclohexyl-p-phenylenediamine, N,N′-diphenyl-p-phenylenediamine, N,N′-bis(2-naphthyl)-p-phenylenediamine, N-isopropyl-N′-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine, N-(1-methylheptyl)-N′-phenyl-p-phenylenediamine, N-cyclohexyl-N′-phenyl-p-phenylenediamine, 4-(p-toluenesulfamoyl)diphenylamine, N,N′-dimethyl-N,N′-di-sec-butyl-p-phenylenediamine, diphenylamine, N-allyldiphenylamine, 4-isopropoxydiphenylamine, N-phenyl-1-naphthylamine, N-(4-tert-octylphenyl)-1-naphthylamine, N-phenyl-2-naphthylamine, octylated diphenylamine, for example p,p′-di-tert-octyldiphenylamine, 4-n-butylaminophenol, 4-butyrylaminophenol, 4-nonanoylaminophenol, 4-dodecanoylaminophenol, 4-octadecanoylaminophenol, bis(4-methoxyphenyl)amine, 2,6-di-tert-butyl-4-dimethylaminomethylphenol, 2,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, N,N,N′,N′-tetramethyl-4,4′-diaminodiphenylmethane, 1,2-bis[(2-methylphenyl)amino]ethane, 1,2-bis(phenylamino)propane, (o-tolyl)biguanide, bis[4-(1′,3′-dimethylbutyl)phenyl]amine, tert-octylated N-phenyl-1-naphthylamine, a mixture of mono- and dialkylated tert-butyl/tert-octyldiphenylamines, a mixture of mono- and dialkylated nonyldiphenylamines, a mixture of mono- and dialkylated dodecyldiphenylamines, a mixture of mono- and dialkylated isopropyl/isohexyldiphenylamines, a mixture of mono- und dialkylated tert-butyldiphenylamines, 2,3-dihydro-3,3-dimethyl-4H-1,4-benzothiazine, phenothiazine, a mixture of mono- und dialkylated tert-butyl/tert-octylphenothiazines, a mixture of mono- und dialkylated tert-octyl-phenothiazines, N-allylphenothiazin, N,N,N′,N′-tetraphenyl-1,4-diaminobut-2-ene, N,N-bis-(2,2,6,6-tetramethyl-piperid-4-yl-hexamethylenediamine, bis(2,2,6,6-tetramethylpiperid-4-yl)-sebacate, 2,2,6,6-tetramethylpiperidin-4-one, 2,2,6,6-tetramethylpiperidin-4-ol.

2. Phosphites and phosphonites, for example triphenyl phosphite, diphenyl alkyl phosphites, phenyl dialkyl phosphites, tris(nonylphenyl) phosphite, trilauryl phosphite, trioctadecyl phosphite, distearyl pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite, diisodecyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)-pentaerythritol diphosphite, diisodecyloxypentaerythritol diphosphite, bis(2,4-di-tert-butyl-6-methylphenyl)pentaerythritol diphosphite, bis(2,4,6-tris(tert-butylphenyl)pentaerythritol diphosphite, tristearyl sorbitol triphosphite, tetrakis(2,4-di-tert-butylphenyl) 4,4′-biphenylene diphosphonite, 6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenz[d,g]-1,3,2-dioxaphosphocin, 6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-dibenz[d,g]-1,3,2-dioxaphosphocin, bis(2,4-di-tert-butyl-6-methylphenyl) methyl phosphite, bis(2,4-di-tert-butyl-6-methylphenyl) ethyl phosphite, 2,2′,2″-nitrilo[triethyltris(3,3′,5,5′-tetra-tert-butyl-1,1′-biphenyl-2,2′-diyl)phosphite], 2-ethylhexyl(3,3′,5,5′-tetra-tert-butyl-1,1′-biphenyl-2,2′-di-yl)phosphite.

Especially preferred are the following phosphites:

Tris(2,4-di-tert-butylphenyl) phosphite (Irgafos®168, Ciba-Geigy), tris(nonylphenyl) phosphite,

3. Hydroxylamines, for example, N,N-dibenzylhydroxylamine, N,N-diethylhydroxylamine, N,N-dioctylhydroxylamine, N,N-dilaurylhydroxylamine, N,N-ditetradecylhydroxylamine, N,N-dihexadecylhydroxylamine, N,N-dioctadecylhydroxylamine, N-hexadecyl-N-octadecylhydroxylamine, N-heptadecyl-N-octadecylhydroxylamine, N,N-dialkylhydroxylamine derived from hydrogenated tallow amine.

4. Nitrones, for example, N-benzyl-alpha-phenyl-nitrone, N-ethyl-alpha-methyl-nitrone, N-octyl-alpha-heptyl-nitrone, N-lauryl-alpha-undecyl-nitrone, N-tetradecyl-alpha-tridcyl-nitrone, N-hexadecyl-alpha-pentadecyl-nitrone, N-octadecyl-alpha-heptadecyl-nitrone, N-hexadecyl-alpha-heptadecyl-nitrone, N-ocatadecyl-alpha-pentadecyl-nitrone, N-heptadecyl-alpha-heptadecyl-nitrone, N-octadecyl-alpha-hexadecyl-nitrone, nitrone derived from N,N-dialkylhydroxylamine derived from hydrogenated tallow amine.

5. Nucleating agents, for example, inorganic substances such as talcum, metal oxides such as titanium dioxide or magnesium oxide, phosphates, carbonates or sulfates of, preferably, alkaline earth metals; organic compounds such as mono- or polycarboxylic acids and the salts thereof, e.g. 4-tert-butylbenzoic acid, adipic acid, diphenylacetic acid, sodium succinate or sodium benzoate; polymeric compounds such as ionic copolymers (ionomers).

6. Fillers and reinforcing agents, for example, calcium carbonate, silicates, glass fibres, glass bulbs, asbestos, talc, kaolin, mica, barium sulfate, metal oxides and hydroxides, carbon black, graphite, wood flour and flours or fibers of other natural products, synthetic fibers.

7. Other additives, for example, plasticisers, lubricants, emulsifiers, pigments, rheology additives, catalysts, flow-control agents, optical brighteners, flameproofing agents, antistatic agents and blowing agents.

8. Benzofuranones and indolinones, for example those disclosed in U.S. Pat. NoS. 4,325,863; 4,338,244; 5,175,312; 5,216,052; 5,252,643; DE-A-4316611; DE-A-4316622; DE-A-4316876; EP-A-0589839 or EP-A-0591102 or 3-[4-(2-acetoxyethoxy)-phenyl]-5,7-di-tert-butyl-benzofuran-2-one, 5,7-di-tert-butyl-3-[4-(2-stearoyloxyethoxy)phenyl]benzofuran-2-one, 3,3′-bis[5,7-di-tert-butyl-3-(4-[2-hydroxyethoxy]phenyl)benzofuran-2-one], 5,7-di-tert-butyl-3-(4-ethoxyphenyl)benzofuran-2-one, 3-(4-acetoxy-3,5-dimethylphenyl)-5,7-di-tert-butyl-benzofuran-2-one, 3-(3,5-dimethyl-4-pivaloyloxyphenyl)-5,7-di-tert-butyl-benzofuran-2-one, 3-(3,4-dimethylphenyl)-5,7-di-tert-butyl-benzofuran-2-one, 3-(2,3-di-methylphenyl)-5,7-di-tert-butyl-benzofuran-2-one.

A further subject of the invention is the use of a mixture of UV-absorbers as defined above for the stabilization of polyolefins.

The following examples illustrate the invention.

EXAMPLE 1 Light Stabilization of PP Homopolymer Films

100 parts of unstabilized polypropylene powder (melt flow index 3.2 g/10 minutes, 230° C./2160 g) are homogenized at 200° C. for 10 minutes in a Brabender plastograph with 0.05 parts of pentaerythrityl-tetrakis-3-(3,5-ditert.butyl-4-hydroxyphenyl)-propionate, 0.05 parts of tris-(2,4-di-tert.butylphenyl )-phosphite, 0.1 parts of Ca stearate and the amount of light stabilizer indicated in table 1. The material thus obtained is compression molded in a laboratory press between two aluminum foils for 6 minutes at 260° C. to a 0.5 mm thick film which is cooled immediately to room temperature in a water-cooled press. Samples of 60×25 mm are cut out of these 0.5 mm films and exposed in a WEATHER-OMETER Ci 65 (black panel temperature 63±2° C., without water-spraying)

Periodically, these samples are removed from the exposure apparatus and their carbonyl content is measured with an infrared spectrophotometer.

The exposure time corresponding to formation of a carbonyl absorbance of 0.1 is a measure for the stabilizing efficiency of the light stabilizer. The values obtained are summarized in the following table (Table 1).

TABLE 1

Performance in PP Homopolymer 0.5 mm Thick Films

		Calculated
	T0.1: (h)	additive effect
	WEATHER-	of
Stabilization	OMETER Ci 65	combinations

Control	120	—
0.2% CHIMASSORB 81	410	—
0.2% TINUVIN 326	430	—
0.2% TINUVIN 1577	570	—
0.2% TINUVIN 315	905	—
0.1% CHIMASSORB 81 + 0.1%	650	490
TINUVIN 1577
0.1% CHIMASSORB 81 + 0.1%	770	657
TINUVIN 315
0.1% TINUVIN 326 + 0.1%	705	667
TINUVIN 315
0.1% TINUVIN 1577 + 0.1%	810	737
TINUVIN 315

EXAMPLE 2 Light Stabilization of PP Homopolymer Films

100 parts of unstabilized polypropylene powder (melt flow index 12 g/10 minutes, 230°C./2160 g) are homogenized at 200° C. for 10 minutes in a Brabender plastograph with 0.05 parts of pentaerythrityl-tetrakis-3-(3,5-ditert.butyl-4-hydroxyphenyl)-propionate, 0.05 parts of tris-(2,4-di-tert.butylphenyl )-phosphite, 0.1 parts of Ca stearate and the amount of light stabilizer indicated in table 2. The material thus obtained is compression molded in a laboratory press between two aluminum foils for 6 minutes at 260° C. to a 0.1 mm thick film, which is cooled immediately to room temperature in a water-cooled press. Samples of 60×25 mm are cut out of these 0.1 mm films and exposed in a XENOTEST 1200 (black panel temperature 53±2° C., without water-spraying).

The exposure time corresponding to formation of a carbonyl absorbance of 0.1 is a measure for the stabilizing efficiency of the light stabilizer. The values obtained are summarized in the following table (Table 2).

TABLE 2

Light Stabilization of PP Homopolymer Films

	T0.1: (h)	Calculated
	XENOTEST	additive effect of
Stabilization	1200	combinations

Control	300	—
0.6% CHIMASSORB 81	3120	—
0.6% TINUVIN 327	440	—
0.6% TINUVIN 315	1090	—
0.3% CHIMASSORB 81 + 0.3%	2650	2105
TINUVIN 315
0.3% TINUVIN 327 + 0.3%	940	765
TINUVIN 315
0.2% CHIMASSORB 81 + 0.2%	1870	1550
TINUVIN 327 + 0.2% TINUVIN 315
0.4% CHIMASSORB 81 + 0.1%	2925	2335
TINUVIN 327 + 0.1% TINUVIN 315
0.3% CHIMASSORB 81 + 0.15%	2720	2030
TINUVIN 327 + 0.15% TINUVIN 315

EXAMPLE 3 Light Stabilization of PE-HD Films (Phillips-type)

100 parts of a Phillips-type high density polyethylene powder (density: 0.965, melt flow index 6.0 g/10 minutes, 190° C./2160 g) stabilized with 0.05 parts of pentaerythrityl-tetrakis-3-(3,5-ditert.butyl-4-hydroxyphenyl)-propionate and 0.1 parts of Ca stearate are homogenized at 180° C. for 10 minutes in a Brabender plastograph with the amount of light stabilizer and coadditives indicated in table 3. Similarly 100 parts of a Ziegler-type high density polyethylene powder (density: 0.961, melt flow index 6.0 g/10 minutes, 190° C./2160 g) stabilized with 0.05 parts of pentaerythrityl-tetrakis-3-(3,5-ditert.butyl-4-hydroxyphenyl)-propionate, 0.05 parts tris-(2,4-di-tert.butylphenyl)-phosphite and 0.1 parts of Ca stearate are homogenized at 180° C. for 10 minutes in a Brabender plastograph with the amount of light stabilizer and coadditives indicated in table 3a.

The material thus obtained is compression molded in a laboratory press between two aluminum foils for 6 minutes at 210° C. to a 0.2 mm thick film which is cooled immediately to room temperature in a water-cooled press. Samples of 60×25 mm are cut out of these 0.2 mm films and exposed in a XENOTEST 1200 (black panel temperature 53±2° C., without water spraying). Periodically, these samples are removed from the exposure apparatus and their carbonyl content is measured with an infrared spectrophotometer. The exposure time corresponding to formation of a carbonyl absorbance of 0.1 is a measure for the stabilizing efficiency of the light stabilizer. The values obtained are summarized in the following tables 3 and 3a.

TABLE 3

Light Stabilization of 0.2 mm Thick PE-HD Films (Phillips Type)

		Calculated
	T_0.1: (h)	additive effect
	XENOTEST	of
Stabilization	1200	combinations

Control	360	—
0.3% CHIMASSORB 81	2230	—
0.3% TINUVIN 327	1240	—
0.3% TINUVIN 315	2020	—
0.15% CHIMASSORB 81 + 0.15%	3000	1735
TINUVIN 327
0.15% CHIMASSORB 81 + 0.15%	2650	2125
TINUVIN 315
0.15% TINUVIN 327 + 0.15%	3060	1630
TINUVIN 315
0.1% CHIMASSORB 81 + 0.1%	3150	1830
TINUVIN 327 + 0.1% TINUVIN 315

TABLE 3a

Light stabilization of 0.2 mm Thick PE-HD Films (Ziegler Type)

		Calculated
	T_0.1: (h)	additive effect
Stabilization	XENOTEST	of
Comparative Experiment	1200	combinations

Control	190	—
0.3% CHIMASSORB 81	1540	—
0.3% TINUVIN 327	700	—
0.15% CHIMASSORB 81 + 0.15%	940	1120
TINUVIN 327

EXAMPLE 4 Light Stabilization of PE-LD Films

100 parts of unstabilized low density polyethylene powder (density: 0.918, melt flow index 0.3 g/10 minutes at 190° C./2160 g) are homogenized at 180° C. for 10 minutes in a Brabender plastograph with 0.02 parts of octadecyl 3-(3,5-di-tert.-butyl-4-hydroxyphenyl)-propionate, 0.08 parts of tris-(2,4-di-tert.butylphenyl)-phosphite and the amount of light stabilizer indicated in the table. The material thus obtained is compression molded in a laboratory press between two aluminum foils for 6 minutes at 170° C. to a 0.5 mm thick film which is quenched immediately in cold water. Samples of 60×25 mm are cut out of these 0.5 mm films and exposed in a WEATHER-OMETER Ci 65 (black panel temperature 63±2° C., without water-spraying).

The exposure time corresponding to formation of a carbonyl absorbance of 0.1 is a measure for the stabilizing efficiency of the light stabilizer. The values obtained are summarized in the following table.

TABLE 4

Light Stabilization of PE-LD Films

		Calculated
	T0.1: (h)	additive
	WEATHER-	effect of
Stabilization	OMETER Ci 65	combinations

Control	150	—
0.1% CHIMASSORB 81	430	—
0.2% CHIMASSORB 81	665	—
0.1% TINUVIN 326	760	—
0.2% TINUVIN 326	1150	—
0.1% TINUVIN 1577	815	—
0.2% TINUVIN 1577	1100	—
0.1% TINUVIN 315	705	—
0.2% TINUVIN 315	2000	—
0.05% CHIMASSORB 81 + 0.05%	665	622
TINUVIN 1577
0.05% CHIMASSORB 81 + 0.05%	780	567
TINUVIN 315
0.05% TINUVIN 326 + 0.05%	795	732
TINUVIN 315
0.05% TINUVIN 1577 + 0.05%	830	760
TINUVIN 315
0.1% CHIMASSORB 81 + 0.1%	920	882
TINUVIN 1577
0.1% CHIMASSORB 81 + 0.1%	1660	1332
TINUVIN 315

EXAMPLE 5 Light Stabilization of PE-LLD Films

100 parts of unstabilized linear low density polyethylene (PE-LLD) powder (density: 0.920, melt flow index 1.0 g/10 minutes at 190° C./2160 g) are homogenized at 180° C. for 10 minutes in a Brabender plastograph with 0.02 parts octadecyl 3-(3,5-di-tert.-butyl-4-hydroxyphenyl)-propionate, 0.08 parts tris-(2,4-di-tert.butylphenyl)-phosphite, 0.1 parts Ca stearate and the amounts light stabilizers indicated in table 5. Similarly 100 parts of unstabilized metallocene polyethylene powder (density: 0.905, 10% butene comonomer, melt flow index 1.4 g/10 minutes at 190° C./2160 g) are homogenized at 180° C. for 10 minutes in a Brabender plastograph with 0.02 parts octadecyl 3-(3,5-di-tert.-butyl-4-hydroxyphenyl)-propionate, 0.08 parts tris-(2,4-di-tert.butylphenyl)-phosphite, 0.1 parts Ca stearate and the amounts light stabilizers indicated in table 5a (see also example 6). The material thus obtained is compression molded in a laboratory press between two aluminum foils for 6 minutes at 170° C. to a 0.5-mm thick film, which is quenched immediately in cold water. Samples of 60×25 mm are cut out of these 0.5 mm films and exposed in a WEATHER-OMETER Ci 65 (black panel temperature 63±2° C., without water-spraying).

The exposure time corresponding to formation of a carbonyl absorbance of 0.1 is a measure for the stabilizing efficiency of the light stabilizer. The values obtained are summarized in the following tables 5 and 5a.

TABLE 5

Light Stabilization of PE-LLD Conventional Type

	T0.1: (h)	Calculated
	WEATHER-	additive effect of
Stabilization	OMETER Ci 65	combinations

Control	260	—
0.2% CHIMASSORB 81	2260	—
0.2% TINUVIN 326	1350	—
0.2% TINUVIN 1577	1600	—
0.2% TINUVIN 315	2840	—
0.1% CHIMASSORB 81 + 0.1%	3300	2550
TINUVIN 315
0.1% TINUVIN 326 + 0.1%	2820	2095
TINUVIN 315
0.1% TINUVIN 1577 + 0.1%	2920	2220
TINUVIN 315

TABLE 5a

Comparison Between PE-LLD Metallocene
Type and Conventional PE-LLD for Combinations Benzophenon/
Benzotriazol UV-Absorber (data partly from table 5 and 6)

	T0.1: (h)	Calculated
Stabilization	WEATHER-	additive effect of
metallocene PE-LLD	OMETER Ci 65	combinations

Control	365	—
0.2% CHIMASSORB 81	1920	—
0.2% TINUVIN 326	1480	—
0.1% CHIMASSORB 81 + 0.1%	1880	1700
TINUVIN 326
Comparative example
with conventional PE-LLD
Control	260	—
0.2% CHIMASSORB 81	2260	—
0.2% TINUVIN 326	1350	—
0.1% CHIMASSORB 81 + 0.1%	1390	1805
TINUVIN 326

EXAMPLE 6 Light Stabilization of Metallocene-PE Films

100 parts of unstabilized metallocene polyethylene powder (density: 0.905, 10% butene comonomer) are homogenized at 180° C. for 10 minutes in a Brabender plastograph with 0.02 parts of octadecyl 3-(3,5-di-tert.-butyl-4-hydroxyphenyl)-propionate, 0.08 parts of tris-(2,4-di-tert.butylphenyl)-phosphite, 0.1 part of Ca stearate and the amount of light stabilizer indicated in the table. The material thus obtained is compression molded in a laboratory press between two aluminum foils for 6 minutes at 170° C. to a 0.2 mm thick film which is quenched immediately in cold water. Samples of 60×25 mm are cut out of these 0.2 mm films and exposed in a WEATHER-OMETER Ci 65 (black panel temperature 63±2° C., without water-spraying).

TABLE 6

Light Stabilization of Metallocene Polyethylene (m-PE-LLD)

		Calculated
	T0.1: (h)	additive effect
	WEATHER-	of
Stabilization	OMETER Ci 65	combinations

Control	365	—
0.2% CHIMASSORB 81	1920	—
0.2% TINUVIN 326	1480	—
0.2% TINUVIN 1577	1800	—
0.2% TINUVIN 315	3380	—
0.1% CHIMASSORB 81 + 0.1%	1880	1700
TINUVIN 326
0.1% CHIMASSORB 81 + 0.1%	2060	1860
TINUVIN 1577
0.1% CHIMASSORB 81 + 0.1%	3440	2650
TINUVIN 315

EXAMPLE 7 Light Stabilization of PE-HD Films

100 parts unstabilized high density polyethylene powder (density: 0.965, melt flow index 2.9 g/10 minutes, 190° C./5 kg) are homogenized at 180° C. for 10 minutes in a Brabender plastograph with the amount of light stabilizer indicated in the table. The material thus obtained is compression molded in a laboratory press between two aluminum foils for 6 minutes at 210° C. to a 0.2 mm thick film which is cooled immediately to room temperature in a water-cooled press. Samples of 60×25 mm are cut out of these 0.2 mm films and exposed in a WEATHER-OMETER Ci 65 (black panel temperature 63±2° C., without water spraying).

TABLE 7

Light stabilization of 0.2 mm thick PE-HD films

		Calculated
		additive effect
	T_0.1: (h) Wather-	of
Stabilization	Ometer	combinations

Control	280	—
0.3% CHIMASSORB 81	4021	—
0.3% TINUVIN 327	580	—
0.3% TINUVIN 315	2223	—
0.3% TINUVIN 1577	476	—
0.15% CHIMASSORB 81 + 0.15%	3616	3122
TINUVIN 315
0.15% CHIMASSORB 81 + 0.15%	2560	2248
TINUVIN 1577
0.15% TINUVIN 327 + 0.15%	2496	1401
TINUVIN 315
0.15% TINUVIN 315 + 0.15%	3208	1349
TINUVIN 1577
0.1% CHIMASSORB 81 + 0.1%	3136	2275
TINUVIN 327 + 0.1%
TINUVIN 315
0.1% CHIMASSORB 81 + 0.1%	3314	2240
TINUVIN 1577 + 0.1%
TINUVIN 315
0.1% TINUVIN 327 + 0.1%	1948	1093
TINUVIN 1577 + 0.1%
TINUVIN 315

EXAMPLE 8 Light Stabilization of Metallocene-PE-LLD Films

100 parts of unstabilized metallocene polyethylene powder (density: 0.934, melt flow index 6.0 g/10 minutes, 190° C./2160 g) are homogenized at 180° C. for 10 minutes in a Brabender plastograph with the amount of light stabilizer indicated in the table. The material thus obtained is compression molded in a laboratory press between two aluminum foils for 6 minutes at 170° C. to a 0.2 mm thick film which is quenched immediately in cold water. Samples of 60×25 mm are cut out of these 0.2 mm films and exposed in a WEATHER-OMETER Ci 65 (black panel temperature 63±2° C., without water-spraying).

TABLE 8

Light stabilization of metallocene polyethylene

		Calculated
	T0.1: (h)	additive effect
	WEATHER-	of
Stabilization	OMETER Ci 65	combinations

Control	136	—
0.3% CHIMASSORB 81	1803	—
0.3% TINUVIN 327	473	—
0.3% TINUVIN 1577	324	—
0.3% TINUVIN 315	1903	—
0.15% CHIMASSORB 81 + 0.15%	1196	1063
TINUVIN 1577
0.15% CHIMASSORB 81 + 0.15%	2293	1853
TINUVIN 315
0.15% TINUVIN 327 + 0.15%	1311	1188
TINUVIN 315
0.1% CHIMASSORB 81 + 0.1%	1637	1393
TINUVIN 327 + 0.1%
TINUVIN 315

All compounds used are commercial UV-absorbers from Ciba Specialty Chemicals Inc. and the trade names are registered trade marks.

Claims

1. A polyolefin composition wherein the polyolefin is polyethylene or polypropylene, which comprises as UV absorber a mixture of

a) at least one hydroxybenzophenone and at least one 2-hydroxyphenylbenzotriazole with the proviso that the polyolefin is a high density polyethylene prepared with a Phillips catalyst;

b) at least one hydroxybenzophenone and at least one 2-hydroxyphenyltriazine, with the proviso that if the polyolefin is polypropylene, no polyvinylpyridin is present;

c) at least one hydroxybenzophenone and at least one oxanilide;

e) at least one 2-hydroxyphenyltriazine and at least one oxanilide;

f) at least one hydroxybenzophenone, at least one 2-hydroxyphenylbenzotriazole and at least one oxanilide;

g) at least one hydroxybenzophenone, at least one oxanilide and at least one 2-hydroxyphenyltriazine; or

h) at least one 2-hydroxyphenylbenzotriazole, at least one oxanilide and at least one 2-hydroxy phenyltriazine;

wherein

the hydroxybenzophenone is selected from the group consisting of 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2-hydroxy-4-decyloxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 4,2′,4′-trihydroxybenzophenone and 2′-hydroxy-4,4′-dimethoxybenzophenone;

the 2-hydroxyphenylbenzotriazole is selected from the group consisting of 2-(2′-hydroxy-5′-methylphenyl)-benzotriazole, 2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)benzotriazole, 2-(5′-tert-butyl-2′-hydroxyphenyl)benzotriazole, 2-(2′-hydroxy-5-(1,1,3,3-tetramethylbutyl)phenyl)benzotriazole, 2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)-5-chloro-benzotriazole, 2-(3′-tert-butyl-2′-hydroxy-5′-methylphenyl)-5-chloro-benzotriazole, 2-(3′-sec-butyl-5′-tert-butyl-2′-hydroxyphenyl)benzotriazole, 2-(2′-hydroxy-4′-octyloxyphenyl)benzotriazole, 2-(3′,5′-di-tert-amyl-2′-hydroxyphenyl)benzotriazole, 2-(3′,5′-bis-(α,α-dimethylbenzyl)-2′-hydroxyphenyl)benzotriazole, 2-(3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl)-5-chloro-benzotriazole, 2-(3′-tert-butyl-5′-[2-(2-ethylhexyloxy)-carbonylethyl]-2′-hydroxyphenyl)-5-chloro-benzotriazole, 2-(3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)-5-chloro-benzotriazole, 2-(3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)phenyl)benzotriazole, 2-(3′-tert-butyl-2′-hydroxy-5′-(2-octyloxy-carbonylethyl)phenyl)benzotriazole, 2-(3′-tert-butyl-5′-[2-(2-ethylhexyloxy)carbonylethyl]-2′-hydroxyphenyl)benzotriazole, 2-(3′-dodecyl-2′-hydroxy-5′-methylphenyl)benzotriazole, 2-(3′-tert-butyl-2′-hydroxy-5′-(2-isooctyloxycarbonylethyl)phenylbenzotriazole, 2,2′-methylene-bis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazole-2-ylphenol]; the transesterification product of 2-[3′-tert-butyl-5′-(2-methoxycarbonylethyl)-2′-hydroxyphenyl]-2H-benzotriazole with polyethylene glycol 300;

[R—CH₂CH₂—COO—CH₂CH₂₂where R=3′-tert-butyl-4′-hydroxy-5′-2H-benzotriazol-2-ylphenyl, 2-[2′-hydroxy-340-(α,α-dimethylbenzyl)-5′-(1,1,3,3-tetramethylbutyl)phenyl]benzotriazole and 2-[2′-hydroxy-3′-(1,1,3,3-tetramethylbutyl)-5′-(α,α-dimethylbenzyl)-phenyl]benzotriazole;

the 2-hydroxyphenyltriazine is selected from the group consisting of 2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-propyloxyphenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(4-methylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-tridecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-butyloxy-propoxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-octyloxy-propyloxy)phenyl]-4,6-bi(2,4-dimethyl)-1,3,5-triazine, 2-[4-(dodecyloxy/tridecyloxy-2-hydroxypropoxy)-2-hydroxy-phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-dodecyloxy-propoxy)phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-hydroxy)phenyl-4,6-diphenyl-1,3,5-triazine, 2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-1,3,5-triazine, 2,4,6-tris[2-hydroxy-4-(3-butoxy-propoxy)phenyl]-1,3,5-triazine, 2-(2-hydroxyphenyl)-4-(4-methoxyphenyl)-6-phenyl-1,3,5-triazine, and 2-{2-hydroxy-4-[3-(2-ethylhexyl-1-oxy)-2-hydroxypropyloxy]phenyl)}-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine;

and the oxanilide is selected from the group consisting of 4,4′-dioctyloxyoxanilide, 2,2′-diethoxyoxanilide, 2,2′-dioctyloxy-5,5′-di-tert-butoxanilide, 2,2′-didodecyloxy-5,5′-di-tert-butoxanilide, 2-ethoxy-2′-ethyloxanilide, N,N′-bis(3-dimethylaminopropyl)oxamide, 2-ethoxy-5-tert-butyl-2′-ethoxanilide and its mixture with 2-ethoxy-2′-ethyl-5,4′-di-tert-butoxanilide, mixtures of o- and p-methoxy-disubstituted oxanilides and mixtures of o- and p-ethoxy-disubstituted oxanilides.

2. A polyolefin composition according to claim 1 wherein the amount of the individual UV absorber in the mixture is from 20% to 80% based on the weight of the mixture, with the proviso that the sum adds to 100%.

3. A polyolefin composition according to claim 1 wherein the total amount of UV-absorber is from 0.005 to 5% based on the weight of the polymer.

4. A polyolefin composition according to claim 1, which additionally contains at least one sterically hindered amine containing at least one radical of the formula

in which R is hydrogen or methyl.